Coach

(A) A private tutor The term is a pun on getting on
fast. To get on fast you take a coach, you cannot get on fast
without a private tutor —ergo, a private tutor is the coach you
take in order that you may get on quickly. (University slang.)

“The books are expensive, and often a further expense is entailed by
the necessity of securing `a coach.' ” —Stedman Oxford, chap.
x. p. 188.

To dine in the coach.

In the captain's private room. The coach or couch of a ship is a
small apartment near the stern, the floor being formed of the aftmost
part of the quarter-deck, and the roof by the poop.